The 2007 GMAC Insurance National Drivers Test found that one in six drivers on the road would not pass their written driver's exam if they had to take it today, GMAC said Thursday in a release.

New York drivers came in last in driver knowledge, while Idaho came in first.

Arkansas, Minnesota, Kansas and Wisconsin ranked in the top five, while New Jersey, the District of Columbia, Massachusetts and Rhode Island were in the bottom five among all 50 states.

"All Americans need a refresher course when it comes to basic driving rules," said Gary Kusumi, president of GMAC Insurance, Personal Lines. "Being a safe driver is about conduct, judgment and knowledge. We're hoping this year's results encourage people to arm themselves with the knowledge they need to stay safe."

GMAC said 81 percent of people couldn't identify the proper following distance from the car in front of them (2 seconds) and 84 percent couldn't identify the correct action to take when approaching a steady yellow traffic light (stop if it is safe to do so).